This invention relates generally to improvements in writing implements of the general type including ink pens, pencils, felt tip markers, and other types of writing implements. More specifically, this invention relates to an improved writing implement having a deformable grip responsive to user fingertip pressure to assume a highly comfortable and low fatigue geometric configuration.
A wide variety of different kinds of writing implements are well known to include many different types of ink pens, pencils, and various other forms of marking implements. Such writing implements typically comprise a generally cylindrical or barrellike elongated body carrying a marking medium, for example, a ball point pen cartridge having a porous ball writing tip exposed at the end of a long and thin ink-containing cylinder. The implement body is traditionally grasped by the fingertips at a position near the writing tip to facilitate implement manipulation during movement of the writing tip over the surface of a marking medium such as paper or the like.
The generally cylindrical body of a writing implement may be formed in a wide variety of different sizes and specific geometric shapes. In this regard, it is generally recognized that the size and shape of most writing implements is not adapted for prolonged use without experiencing a relatively high degree of user fatigue and discomfort, sometimes referred to as writer's cramp. In attempts to alleviate this situation, many writing implements are provided with contoured grip surfaces of many different sizes and shapes, with some of such contoured grip surfaces constituting complex molded surfaces aimed at approximating the anatomical contours of a writer's fingertips during grasping of the writing implement. However, these grip surface configurations have achieved only limited success in relieving writer's fatigue since, among other reasons, the grip surface is unable to match the differing anatomical shapes and pen grasping techniques of different individuals.
Some writing implements have been provided with resilient grip surfaces as an alternative approach to achieving enhanced comfort and reduced fatigue during use. For the most part, these resilient grip surfaces include sleevelike structures mounted about the body of a writing implement to provide a cushioned grip surface with at least some yield in response to fingertip pressure when the writing implement is gripped. In some cases, air chambers have been proposed between the resilient sleeve and the implement body for increased overall cushioning effect. However, while this approach may achieve some improvements in user comfort, the resilient sleeve is unable to undergo significant shape change when gripped, whereby the sleeve cannot accommodate a truly customized geometry tailored to the individual user. The resilient nature of the sleeve results in reaction forces applied to the user's fingertips urging the sleeve to spring substantially immediately back toward a relaxed or nondeformed state, wherein these reaction forces can themselves contribute to writer's fatigue over a prolonged period of time.
There exists, therefore, a need for further improvements in writing implements, particularly with respect to an improved writing implement designed to achieve significant enhancements in user comfort and reductions in user fatigue. The present invention fulfills these needs and provides further related advantages.